1. Field of the Invention
The invention relates to the optimization of radiant curing of surface coatings on three-dimensional objects and, more particularly, to ultraviolet (UV) curing of surface coatings on three-dimensional objects.
2. Description of the Prior Art
The current methodology for the optimization of UV curing of surface coatings on three-dimensional complex objects using adjustable UV lamps or systems of lamps and reflectors is a complex process usually performed by trial and error guided by heuristic techniques. Such an optimization process is time consuming and is a mistake prone activity. Even when the heuristic optimization results in satisfying minimum curing requirements, the optimization does not provide for an unambiguous curing process specification and yields no information for process control and sensitivity analysis. Consequently, the extensive efforts required for the current state of the art""s optimization of UV curing processes of surface coatings on complex three-dimensional objects generally produces sub-optimal performance, wastes time, space an energy and results in low and unpredictable quality.
The problems of optimization of the curing of surface coatings on three-dimensional objects are known and routinely encountered in applications. The partial solutions for particular aspects of the general problem are extensively discussed. See R. Stowe, xe2x80x9cPractical Aspects of Irradiance and Dose and UV Curingxe2x80x9d, RadTech 98, Chicago, Apr. 19-22, 1998, pp. 640-645, Chicago, RadTech International North America, Northbrook, II 1998. Furthermore, the publication xe2x80x9cOptimized Positioning of UV Lamps for the Treatment 3D Workpiecesxe2x80x9d by Schneider M., Klein W., and Schrxc3x6der C., xe2x80x9cRadTech Europe 99xe2x80x9d, Nov. 8-10, 1999, Berlin RadTech Europe, Nyon, Schweiz, 1999, pages 711-716, describes an attempt to optimize UV curing.
The present invention is a process which provides a systematic approach to the optimization of irradiation and preferably, UV curing of surface coatings on complex 3D objects. The invention avoids the deficiencies and expenses of the prior art ad hoc process of optimization as described above. The present invention is not limited by size and geometry of the lamps, 3D objects and relative positions thereof. The process of the present invention is more time efficient, simultaneously optimizes radiant illumination and radiant chemistry and naturally yields process production design and control parameters. The invention may be utilized with respect to diverse products and applications where treatment of surface coatings on complex 3D geometries of objects is required.
A process for irradiation curing of a coating on a three-dimensional object in accordance with the invention includes (a) providing a model of a radiant output of at least two lamps to be used to provide the irradiation curing of the coating; (b) providing a model of at least one characteristic of a response of the surface to irradiation curing; (c) selecting a radiant output of lamps based upon the model of the radiant output; (d) defining at least a spatial position of the lamps during curing of the coating; (e) defining at least a spatial position of the three-dimensional object during curing of the coating; (f) simulating a radiant output of the at least two lamps based upon the defined spatial position of the lamps; (g) in response to the simulated radiant output and the defined spatial position of the three-dimensional object during curing of the coating, determining if a predicted irradiation from at least two lamps on the coating coated on the three-dimensional object will acceptably cure the coating on the three-dimensional object; and (h) if the radiant output is acceptable, storing a number of the lamps used in the model of the radiant output, the defined position of the lamps used in the model of the radiant output, the selected radiant output, and the defined position of the three-dimensional object. If the radiant output is not acceptable, changing at least one parameter of the process and repeating steps (c)-(h) may be repeated using a new parameter set. The at least one parameter may be the new number of lamps to be selected and thereafter repeating steps (c)-(h). The at least one process parameter may define motion of the lamps during curing of the surface coating and may define motion of the three-dimensional object during curing of the surface coating; and steps (c)-(h) may be repeated. A curing facility having the stored number of lamps, the stored radiance, the stored lamp position and the stored position of the three-dimensional object stored at step (h), may be fabricated and thereafter, used to cure of the surface coating disposed on the three-dimensional object.